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使用phpdbg来调试php程序的方法介绍

PHPDBG是一个PHP的SAPI模块,可以在不用修改代码和不影响性能的情况下控制PHP的运行环境

可以在PHP5.4和之上版本中使用。在PHP5.6和之上版本将内部集成

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功能

  • 单步调试

  • 灵活的下断点方式(类方法、函数、文件:行、内存地址、opcode)

  • 可直接调用php的eval

  • 可以查看当前执行的代码

  • 用户空间API(userland/user space)

  • 方便集成

  • 支持指定php配置文件

  • JIT全局变量

  • readline支持(可选),终端操作更方便

  • 远程debug,使用java GUI

  • 操作简便(具体看help)

安装

如果是PHP56一下

cd /usr/src/php-src/sapigit clone https://github.com/krakjoe/phpdbgcd .././buildconf --force./config.nicemake -j8make install-phpdbg

PHP56的话直接启用phpdbg就可以了

注意: php 配置中可以启用 –with-readline for phpdbg to support history, autocompletion, tab-listing etc

phpdbginit

Setting up your debugging session automatically

phpdbg -imy.phpdbginit

In addition, .phpdbginit can contain embedded code, allowing, for example

  • the setup of auto completion

  • the registration of functions

  • the acquisition and pre-compilation of code

  • bootstrapping a web application

The default .phpdbginit

########################################################### .phpdbginit## Lines starting with # are ignored# Code must start and end with <: and :> respectively########################################################### Place initialization commands one per line########################################################### exec sapi/phpdbg/test.php ########################################################### Embedding code in .phpdbginit##########################################################<:/* If readline is loaded, you might want to setup completion:*/if (function_exists('readline_completion_function')) {    readline_completion_function(function(){        return array_merge(            get_defined_functions()['user'],            array_keys(get_defined_constants())        );    });}:>########################################################### Now carry on initializing phpdbg ...########################################################### R my_debugging_function ########################################################### PHP has many functions that might be useful# ... you choose ...########################################################### R touch# R unlink# R scandir# R glob ########################################################### Remember: *you have access to the shell*########################################################### The output of registered function calls is not,# by default, very pretty (unless you implement# and register a new implementation for phpdbg)# The output of shell commands will usually be more# readable on the console########################################################### TLDR; if you have a good shell, use it ...########################################################## 

查看版本号

[root@localhost ~]# php -vPHP 5.6.16 (cli) (built: Dec  8 2015 09:10:23) (DEBUG)Copyright (c) 1997-2015 The PHP GroupZend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies    with Xdebug v2.3.3, Copyright (c) 2002-2015, by Derick Rethans[root@localhost ~]# phpdbg -Vphpdbg 0.4.0 (built: Dec  8 2015 09:10:43)PHP 5.6.16, Copyright (c) 1997-2015 The PHP GroupZend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies    with Xdebug v2.3.3, Copyright (c) 2002-2015, by Derick Rethans

查看help

[root@localhost ~]# phpdbg[Welcome to phpdbg, the interactive PHP debugger, v0.4.0]To get help using phpdbg type "help" and press enter[Please report bugs to <http://github.com/krakjoe/phpdbg/issues>]phpdbg> help phpdbg is a lightweight, powerful and easy to use debugging platform for PHP5.4+It supports the following commands: Information  list     list PHP source  info     displays information on the debug session  print    show opcodes  frame    select a stack frame and print a stack frame summary  back     shows the current backtrace  help     provide help on a topic Starting and Stopping Execution  exec     set execution context  run      attempt execution  step     continue execution until other line is reached  continue continue execution  until    continue execution up to the given location  finish   continue up to end of the current execution frame  leave    continue up to end of the current execution frame and halt after the calling instruction  break    set a breakpoint at the specified target  watch    set a watchpoint on $variable  clear    clear one or all breakpoints  clean    clean the execution environment Miscellaneous  set      set the phpdbg configuration  source   execute a phpdbginit script  register register a phpdbginit function as a command alias  sh       shell a command  ev       evaluate some code  quit     exit phpdbg Type help <command> or (help alias) to get detailed help on any of the above commands, for example help list or h l.  Note that help will also match partial commands if unique (and listout options if not unique), so help clea will give help on the clean command, but help cl will list the summary for clean and clear. Type help aliases to show a full alias list, including any registered phpdginit functionsType help syntax for a general introduction to the command syntax.Type help options for a list of phpdbg command line options.Type help phpdbginit to show how to customise the debugger environment.phpdbg> help listCommand: list  Alias: l  lists some code The list command displays source code for the given argument.  The target type is specficied by a second subcommand keyword:   Type     Alias  Purpose  lines    l      List N lines from the current execution point  func     f      List the complete source for a specified function  method   m      List the complete source for a specified class::method  class    c      List the complete source for a specified class Note that the context of lines, func and method can be determined by parsing the argument, so these subcommands are optional.  However, you must specify the class keyword to list off aclass. Examples     phpdbg>  list 2    phpdbg>  l l 2    List the next 2 lines from the current file     phpdbg>  list my_function    phpdbg>  l f my_function    List the source of the function my_function     phpdbg>  list func .mine    phpdbg>  l f .mine    List the source of the method mine from the active class in scope     phpdbg>  list m my::method    phpdbg>  l my::method    List the source of my::method     phpdbg>  list c myClass    phpdbg>  l c myClass    List the source of myClass Note that functions and classes can only be listed if the corresponding classes and functions table in the Zend executor has a corresponding entry.  You can use the compile command topopulate these tables for a given execution context.phpdbg> help breakCommand: break  Alias: b  set breakpoint Breakpoints can be set at a range of targets within the execution environment.  Execution will be paused if the program flow hits a breakpoint.  The break target can be one of thefollowing types:   Target   Alias Purpose  at       A     specify breakpoint by location and condition  del      d     delete breakpoint by breakpoint identifier number Break at takes two arguments. The first is any valid target. The second is a valid PHP expression which will trigger the break in execution, if evaluated as true in a boolean context atthe specified target. Note that breakpoints can also be disabled and re-enabled by the set break command. Examples     phpdbg>  break test.php:100    phpdbg>  b test.php:100    Break execution at line 100 of test.php     phpdbg>  break 200    phpdbg>  b 200    Break execution at line 200 of the currently PHP script file     phpdbg>  break \mynamespace\my_function    phpdbg>  b \mynamespace\my_function    Break execution on entry to \mynamespace\my_function     phpdbg>  break classX::method    phpdbg>  b classX::method    Break execution on entry to classX::method     phpdbg>  break 0x7ff68f570e08    phpdbg>  b 0x7ff68f570e08    Break at the opline at the address 0x7ff68f570e08     phpdbg>  break my_function#14    phpdbg>  b my_function#14    Break at the opline #14 of the function my_function     phpdbg>  break \my\class::method#2    phpdbg>  b \my\class::method#2    Break at the opline #2 of the method \my\class::method     phpdbg>  break test.php:#3    phpdbg>  b test.php:#3    Break at opline #3 in test.php     phpdbg>  break if $cnt > 10    phpdbg>  b if $cnt > 10    Break when the condition ($cnt > 10) evaluates to true     phpdbg>  break at phpdbg::isGreat if $opt == 'S'    phpdbg>  break @ phpdbg::isGreat if $opt == 'S'    Break at any opcode in phpdbg::isGreat when the condition ($opt == 'S') is true     phpdbg>  break at test.php:20 if !isset($x)    Break at every opcode on line 20 of test.php when the condition evaluates to true     phpdbg>  break ZEND_ADD    phpdbg>  b ZEND_ADD    Break on any occurence of the opcode ZEND_ADD     phpdbg>  break del 2    phpdbg>  b ~ 2    Remove breakpoint 2 Note: Conditional breaks are costly in terms of runtime overhead. Use them only when required as they significantly slow execution. Note: An address is only valid for the current compilation.phpdbg> help watchCommand: watch  Alias: w  set watchpoint Sets watchpoints on variables as long as they are definedPassing no parameter to watch, lists all actually active watchpoints Format for $variable    $var      Variable $var   $var[]    All array elements of $var   $var->    All properties of $var   $var->a   Property $var->a   $var[b]   Array element with key b in array $var Subcommands of watch:    Type     Alias      Purpose   array       a       Sets watchpoint on array/object to observe if an entry is added or removed   recursive   r       Watches variable recursively and automatically adds watchpoints if some entry is added to an array/object   delete      d       Removes watchpoint Note when recursive watchpoints are removed, watchpoints on all the children are removed too Examples      phpdbg>  watch     List currently active watchpoints      phpdbg>  watch $array     phpdbg>  w $array     Set watchpoint on $array      phpdbg>  watch recursive $obj->     phpdbg>  w r $obj->     Set recursive watchpoint on $obj->      phpdbg>  watch delete $obj->a     phpdbg>  w d $obj->a     Remove watchpoint $obj->a Technical note: If using this feature with a debugger, you will get many segmentation faults, each time when a memory page containing a watched address is hit.                You then you can continue, phpdbg will remove the write protection, so that the program can continue.                If phpdbg could not handle that segfault, the same segfault is triggered again and this time phpdbg will abort.

这些帮助文档足够了

示例代码 testb 与 testa的输出为什么是这样?

<?php ini_set("memory_limit","-1"); class test{     public function testa(){         $a=1;        $b = &$a;        return 0 + (++$a) + (++$a);     }     public function testb(){         $a=1;        $b = &$a;        return ++$a  + (++$a);     }     public function convert($size)    {        $unit=array('b','kb','mb','gb','tb','pb');        return @round($size/pow(1024,($i=floor(log($size,1024)))),2).' '.$unit[$i];    }     public function allsort($arr){        sort($arr);        $len = count($arr)-1;        $rs = array();        $rs[] = $arr;        $x = $len;         while($x > 0){            $y = $x --;            if($arr[$x] < $arr[$y]){                $z = $len;                while($arr[$x] > $arr[$z]){                    $z--;                }                list($arr[$x],$arr[$z]) = array($arr[$z],$arr[$x]);                 for($i=$len;$i>$y;$i--,$y++){                    list($arr[$i],$arr[$y]) = array($arr[$y],$arr[$i]);                }                $x = $len;                $rs[] = $arr;            }         }        return $rs;    }} $s = new test();$resa = $s->testa();$resb = $s->testb();$resc = $s->allsort([1,2,3]);echo $resa,"\n",$resb,"\n";#print_r($resb);

开始调试

[root@localhost ~]# phpdbg -e kk.php[Welcome to phpdbg, the interactive PHP debugger, v0.4.0]To get help using phpdbg type "help" and press enter[Please report bugs to <http://github.com/krakjoe/phpdbg/issues>][Attempting compilation of /root/kk.php][Success]

查看一些当前类的opcode

phpdbg> p c test[User Class: test]Methods (4):        L7-13 test::testa() /root/kk.php                L7      0xb77b553c ZEND_EXT_NOP                   <unused>             <unused>             <unused>                           L9      0xb77b5558 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L9      0xb77b5574 ZEND_ASSIGN                    $a                   C0                   @0                                 L10     0xb77b5590 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L10     0xb77b55ac ZEND_ASSIGN_REF                $b                   $a                   @1                                 L11     0xb77b55c8 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L11     0xb77b55e4 ZEND_PRE_INC                   $a                   <unused>             @2                                 L11     0xb77b5600 ZEND_ADD                       C1                   @2                   @3                                 L11     0xb77b561c ZEND_PRE_INC                   $a                   <unused>             @4                                 L11     0xb77b5638 ZEND_ADD                       @3                   @4                   @5                                 L11     0xb77b5654 ZEND_RETURN                    @5                   <unused>             <unused>                           L13     0xb77b5670 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L13     0xb77b568c ZEND_RETURN                    C2                   <unused>             <unused>                   L15-21 test::testb() /root/kk.php                L15     0xb77b656c ZEND_EXT_NOP                   <unused>             <unused>             <unused>                           L17     0xb77b6588 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L17     0xb77b65a4 ZEND_ASSIGN                    $a                   C0                   @0                                 L18     0xb77b65c0 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L18     0xb77b65dc ZEND_ASSIGN_REF                $b                   $a                   @1                                 L19     0xb77b65f8 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L19     0xb77b6614 ZEND_PRE_INC                   $a                   <unused>             @2                                 L19     0xb77b6630 ZEND_PRE_INC                   $a                   <unused>             @3                                 L19     0xb77b664c ZEND_ADD                       @2                   @3                   @4                                 L19     0xb77b6668 ZEND_RETURN                    @4                   <unused>             <unused>                           L21     0xb77b6684 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L21     0xb77b66a0 ZEND_RETURN                    C1                   <unused>             <unused>                   L23-27 test::convert() /root/kk.php                L23     0xb77b66ec ZEND_EXT_NOP                   <unused>             <unused>             <unused>                           L23     0xb77b6708 ZEND_RECV                      <unused>             <unused>             $size                              L25     0xb77b6724 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L25     0xb77b6740 ZEND_INIT_ARRAY                C0                   <unused>             @0                                 L25     0xb77b675c ZEND_ADD_ARRAY_ELEMENT         C1                   <unused>             @0                                 L25     0xb77b6778 ZEND_ADD_ARRAY_ELEMENT         C2                   <unused>             @0                                 L25     0xb77b6794 ZEND_ADD_ARRAY_ELEMENT         C3                   <unused>             @0                                 L25     0xb77b67b0 ZEND_ADD_ARRAY_ELEMENT         C4                   <unused>             @0                                 L25     0xb77b67cc ZEND_ADD_ARRAY_ELEMENT         C5                   <unused>             @0                                 L25     0xb77b67e8 ZEND_ASSIGN                    $unit                @0                   @1                                 L26     0xb77b6804 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L26     0xb77b6820 ZEND_BEGIN_SILENCE             <unused>             <unused>             @2                                 L26     0xb77b683c ZEND_EXT_FCALL_BEGIN           <unused>             <unused>             <unused>                           L26     0xb77b6858 ZEND_EXT_FCALL_BEGIN           <unused>             <unused>             <unused>                           L26     0xb77b6874 ZEND_SEND_VAL                  C6                   <unused>             <unused>                           L26     0xb77b6890 ZEND_EXT_FCALL_BEGIN           <unused>             <unused>             <unused>                           L26     0xb77b68ac ZEND_EXT_FCALL_BEGIN           <unused>             <unused>             <unused>                           L26     0xb77b68c8 ZEND_SEND_VAR                  $size                <unused>             <unused>                           L26     0xb77b68e4 ZEND_SEND_VAL                  C7                   <unused>             <unused>                           L26     0xb77b6900 ZEND_DO_FCALL                  C8                   <unused>             @3                                 L26     0xb77b691c ZEND_EXT_FCALL_END             <unused>             <unused>             <unused>                           L26     0xb77b6938 ZEND_SEND_VAR_NO_REF           @3                   <unused>             <unused>                           L26     0xb77b6954 ZEND_DO_FCALL                  C9                   <unused>             @4                                 L26     0xb77b6970 ZEND_EXT_FCALL_END             <unused>             <unused>             <unused>                           L26     0xb77b698c ZEND_ASSIGN                    $i                   @4                   @5                                 L26     0xb77b69a8 ZEND_SEND_VAR_NO_REF           @5                   <unused>             <unused>                           L26     0xb77b69c4 ZEND_DO_FCALL                  C10                  <unused>             @6                                 L26     0xb77b69e0 ZEND_EXT_FCALL_END             <unused>             <unused>             <unused>                           L26     0xb77b69fc ZEND_DIV                       $size                @6                   @7                                 L26     0xb77b6a18 ZEND_SEND_VAL                  @7                   <unused>             <unused>                           L26     0xb77b6a34 ZEND_SEND_VAL                  C11                  <unused>             <unused>                           L26     0xb77b6a50 ZEND_DO_FCALL                  C12                  <unused>             @8                                 L26     0xb77b6a6c ZEND_EXT_FCALL_END             <unused>             <unused>             <unused>                           L26     0xb77b6a88 ZEND_END_SILENCE               @2                   <unused>             <unused>                           L26     0xb77b6aa4 ZEND_CONCAT                    @8                   C13                  @9                                 L26     0xb77b6ac0 ZEND_FETCH_DIM_R               $unit                $i                   @10                                L26     0xb77b6adc ZEND_CONCAT                    @9                   @10                  @11                                L26     0xb77b6af8 ZEND_RETURN                    @11                  <unused>             <unused>                           L27     0xb77b6b14 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L27     0xb77b6b30 ZEND_RETURN                    C14                  <unused>             <unused>                   L29-54 test::allsort() /root/kk.php                L29     0xb77b818c ZEND_EXT_NOP                   <unused>             <unused>             <unused>                           L29     0xb77b81a8 ZEND_RECV                      <unused>             <unused>             $arr                               L30     0xb77b81c4 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L30     0xb77b81e0 ZEND_EXT_FCALL_BEGIN           <unused>             <unused>             <unused>                           L30     0xb77b81fc ZEND_SEND_REF                  $arr                 <unused>             <unused>                           L30     0xb77b8218 ZEND_DO_FCALL                  C0                   <unused>             @0                                 L30     0xb77b8234 ZEND_EXT_FCALL_END             <unused>             <unused>             <unused>                           L31     0xb77b8250 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L31     0xb77b826c ZEND_EXT_FCALL_BEGIN           <unused>             <unused>             <unused>                           L31     0xb77b8288 ZEND_SEND_VAR                  $arr                 <unused>             <unused>                           L31     0xb77b82a4 ZEND_DO_FCALL                  C1                   <unused>             @1                                 L31     0xb77b82c0 ZEND_EXT_FCALL_END             <unused>             <unused>             <unused>                           L31     0xb77b82dc ZEND_SUB                       @1                   C2                   @2                                 L31     0xb77b82f8 ZEND_ASSIGN                    $len                 @2                   @3                                 L32     0xb77b8314 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L32     0xb77b8330 ZEND_INIT_ARRAY                <unused>             <unused>             @4                                 L32     0xb77b834c ZEND_ASSIGN                    $rs                  @4                   @5                                 L33     0xb77b8368 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L33     0xb77b8384 ZEND_ASSIGN_DIM                $rs                  <unused>             @6                                 L33     0xb77b83a0 UNKNOWN                        $arr                 @7                   <unused>                           L34     0xb77b83bc ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L34     0xb77b83d8 ZEND_ASSIGN                    $x                   $len                 @8                                 L36     0xb77b83f4 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L36     0xb77b8410 ZEND_IS_SMALLER                C3                   $x                   @9                                 L36     0xb77b842c ZEND_JMPZ                      @9                   J86                  <unused>                           L37     0xb77b8448 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L37     0xb77b8464 ZEND_POST_DEC                  $x                   <unused>             @10                                L37     0xb77b8480 ZEND_ASSIGN                    $y                   @10                  @11                                L38     0xb77b849c ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L38     0xb77b84b8 ZEND_FETCH_DIM_R               $arr                 $x                   @12                                L38     0xb77b84d4 ZEND_FETCH_DIM_R               $arr                 $y                   @13                                L38     0xb77b84f0 ZEND_IS_SMALLER                @12                  @13                  @14                                L38     0xb77b850c ZEND_JMPZ                      @14                  J85                  <unused>                           L39     0xb77b8528 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L39     0xb77b8544 ZEND_ASSIGN                    $z                   $len                 @15                                L40     0xb77b8560 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L40     0xb77b857c ZEND_FETCH_DIM_R               $arr                 $x                   @16                                L40     0xb77b8598 ZEND_FETCH_DIM_R               $arr                 $z                   @17                                L40     0xb77b85b4 ZEND_IS_SMALLER                @17                  @16                  @18                                L40     0xb77b85d0 ZEND_JMPZ                      @18                  J44                  <unused>                           L41     0xb77b85ec ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L41     0xb77b8608 ZEND_POST_DEC                  $z                   <unused>             @19                                L41     0xb77b8624 ZEND_FREE                      @19                  <unused>             <unused>                           L42     0xb77b8640 ZEND_JMP                       J36                                                                          L43     0xb77b865c ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L43     0xb77b8678 ZEND_FETCH_DIM_R               $arr                 $z                   @20                                L43     0xb77b8694 ZEND_INIT_ARRAY                @20                  <unused>             @21                                L43     0xb77b86b0 ZEND_FETCH_DIM_R               $arr                 $x                   @22                                L43     0xb77b86cc ZEND_ADD_ARRAY_ELEMENT         @22                  <unused>             @21                                L43     0xb77b86e8 ZEND_FETCH_DIM_TMP_VAR         @21                  C4                   @23                                L43     0xb77b8704 ZEND_ASSIGN_DIM                $arr                 $z                   @24                                L43     0xb77b8720 UNKNOWN                        @23                  @25                  <unused>                           L43     0xb77b873c ZEND_FETCH_DIM_TMP_VAR         @21                  C5                   @26                                L43     0xb77b8758 ZEND_ASSIGN_DIM                $arr                 $x                   @27                                L43     0xb77b8774 UNKNOWN                        @26                  @28                  <unused>                           L43     0xb77b8790 ZEND_FREE                      @21                  <unused>             <unused>                           L45     0xb77b87ac ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L45     0xb77b87c8 ZEND_ASSIGN                    $i                   $len                 @29                                L45     0xb77b87e4 ZEND_IS_SMALLER                $y                   $i                   @30                                L45     0xb77b8800 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L45     0xb77b881c ZEND_JMPZNZ                    @30                  J79 or J66           <unused>                           L45     0xb77b8838 ZEND_POST_DEC                  $i                   <unused>             @31                                L45     0xb77b8854 ZEND_FREE                      @31                  <unused>             <unused>                           L45     0xb77b8870 ZEND_POST_INC                  $y                   <unused>             @32                                L45     0xb77b888c ZEND_FREE                      @32                  <unused>             <unused>                           L45     0xb77b88a8 ZEND_JMP                       J58                                                                          L46     0xb77b88c4 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L46     0xb77b88e0 ZEND_FETCH_DIM_R               $arr                 $y                   @33                                L46     0xb77b88fc ZEND_INIT_ARRAY                @33                  <unused>             @34                                L46     0xb77b8918 ZEND_FETCH_DIM_R               $arr                 $i                   @35                                L46     0xb77b8934 ZEND_ADD_ARRAY_ELEMENT         @35                  <unused>             @34                                L46     0xb77b8950 ZEND_FETCH_DIM_TMP_VAR         @34                  C6                   @36                                L46     0xb77b896c ZEND_ASSIGN_DIM                $arr                 $y                   @37                                L46     0xb77b8988 UNKNOWN                        @36                  @38                  <unused>                           L46     0xb77b89a4 ZEND_FETCH_DIM_TMP_VAR         @34                  C7                   @39                                L46     0xb77b89c0 ZEND_ASSIGN_DIM                $arr                 $i                   @40                                L46     0xb77b89dc UNKNOWN                        @39                  @41                  <unused>                           L46     0xb77b89f8 ZEND_FREE                      @34                  <unused>             <unused>                           L47     0xb77b8a14 ZEND_JMP                       J61                                                                          L48     0xb77b8a30 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L48     0xb77b8a4c ZEND_ASSIGN                    $x                   $len                 @42                                L49     0xb77b8a68 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L49     0xb77b8a84 ZEND_ASSIGN_DIM                $rs                  <unused>             @43                                L49     0xb77b8aa0 UNKNOWN                        $arr                 @44                  <unused>                           L50     0xb77b8abc ZEND_JMP                       J85                                                                          L52     0xb77b8ad8 ZEND_JMP                       J23                                                                          L53     0xb77b8af4 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L53     0xb77b8b10 ZEND_RETURN                    $rs                  <unused>             <unused>                           L54     0xb77b8b2c ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L54     0xb77b8b48 ZEND_RETURN                    C8                   <unused>             <unused>           phpdbg>

加断点,开始调试

phpdbg> b test::testa[Breakpoint #0 added at test::testa]phpdbg> b test::testb[Breakpoint #1 added at test::testb]phpdbg> b 0xb77b6614[Breakpoint #2 added at 0xb77b6614]phpdbg> b 0xb77b6630[Breakpoint #3 added at 0xb77b6630]

运行、查看代码

phpdbg> r[Breakpoint #0 in test::testa() at /root/kk.php:7, hits: 1] 00006:>00007:         public function testa(){ 00008: 00009:                 $a=1;phpdbg> l test::testa00007:  public function testa(){00008:00009:          $a=1;00010:          $b = &$a;00011:          return 0 + (++$a) + (++$a);00012:00013:  }00014:phpdbg> p s[Stack in test::testa()]        L7-13 test::testa() /root/kk.php                L7      0xb77b553c ZEND_EXT_NOP                   <unused>             <unused>             <unused>                           L9      0xb77b5558 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L9      0xb77b5574 ZEND_ASSIGN                    $a                   C0                   @0                                 L10     0xb77b5590 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L10     0xb77b55ac ZEND_ASSIGN_REF                $b                   $a                   @1                                 L11     0xb77b55c8 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L11     0xb77b55e4 ZEND_PRE_INC                   $a                   <unused>             @2                                 L11     0xb77b5600 ZEND_ADD                       C1                   @2                   @3                                 L11     0xb77b561c ZEND_PRE_INC                   $a                   <unused>             @4                                 L11     0xb77b5638 ZEND_ADD                       @3                   @4                   @5                                 L11     0xb77b5654 ZEND_RETURN                    @5                   <unused>             <unused>                           L13     0xb77b5670 ZEND_EXT_STMT                  <unused>             <unused>             <unused>                           L13     0xb77b568c ZEND_RETURN                    C2                   <unused>             <unused>   <br><br>

继续执行

和gdb一样,phpdbg的继续执行命令也是continue,简写形式为c

查看断点

phpdbg> info b------------------------------------------------Method Breakpoints:#0              test::testa#1              test::testb------------------------------------------------Opline Breakpoints:#2              0xb77b6614#3              0xb77b6630

eval操作

可以执行任意的PHP代码

我们可以看到上面例子 testa 与 testb的区别

L7-13 test::testa() /root/kk.php        L11     0xb77b55e4 ZEND_PRE_INC                   $a                   <unused>             @2        L11     0xb77b5600 ZEND_ADD                       C1                   @2                   @3        L11     0xb77b561c ZEND_PRE_INC                   $a                   <unused>             @4        L11     0xb77b5638 ZEND_ADD                       @3                   @4                   @5L15-21 test::testb() /root/kk.php        L19     0xb77b6614 ZEND_PRE_INC                   $a                   <unused>             @2        L19     0xb77b6630 ZEND_PRE_INC                   $a                   <unused>             @3        L19     0xb77b664c ZEND_ADD                       @2                   @3                   @4

区别在于这里 ZEND_PRE_INC 这一个opcode不同,这个opcode就是 ++$a

testb中当引用存在的时候, $a 先自增了两次,然后再加,所以结果为6,这里应该是PHP本身的问题

这个工具比vld丰富多了,PHP会越来越强大的。

相关推荐:

PHP视频教程:https://www.php.cn/course/list/29/type/2.html

以上就是使用phpdbg来调试php程序的方法介绍的详细内容,更多请关注求知技术网其它相关文章!

文章来源:智云一二三科技

文章标题:使用phpdbg来调试php程序的方法介绍

文章地址:https://www.zhihuclub.com/1683.shtml

关于作者: 智云科技

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